Dry grinding warp preventer

ABSTRACT

A fan unit securable to a grinding wheel of a grinder, the fan providing a cooling breeze directed against the surface being ground, so to keep down the temperature thereof and resultant warpage of the work.

United States Patent Inventor Erich P. Liss 147 Bryan Hill Road, Milford, Conn.

Nov. 13, 1967 Apr. 13, 1971 Appl. No. Filed Patented DRY GRINDING WARP PREVENTER 1 Claim, 7 Drawing Figs.

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Field of Search [56] References Cited UNITED STATES PATENTS 2,599,952 6/1952 Strayer 51/266 2,087,012 7/1937 Zimmerman 51/356X 2,746,220 5/1956 Thomas 51/266 2,573,874 11/1951 Richards 51/266UX 3,187,475 6/1965 Sopcak et a1. 51/356 Primary Examiner-James L. Jones, Jr.

ABSTRACT: A fan unit securable to a grinding wheel of a grinder, the fan providing a cooling breeze directed against the surface being ground, so to keep down the temperature thereof and resultant warpage of the work.

DRY GRINDING WARP PREVENTER This invention relates generally to surface grinders. More specifically it relates to grinding wheels for surface grinders.

A principal object of the present invention is to provide a warp preventer for a surface grinder whereby the work may be maintained in an unheated condition during grinding and thus prevent the development of warpage therein.

Another object is to provide a warp preventer which comprises a fan unit that is attachable to a grinding wheel, the fan unit comprising a means for delivering a breeze of cooling air to the surface of the work being ground.

Yet another object is to provide a warp preventer wherein the fan blades are reciprocally radially extendable and retractable dun'ng rotation to cause air turbulance for increased cooling force.

Other objects are to provide a dry grinding warp preventer which is simple in design, inexpensive to manufacture, rugged in construction, easy to use and efficient in operation.

These and other objects will be readily evident upon a study of the following specification and the accompanying drawing wherein:

FIG. I is an edge elevation view of the present invention shown secured on a grinding wheel;

FIG. 2 is a front view of the fan;

FIG. 3 is a fragmentary front view of a modified form of the invention;

FIG. 4 is a front view of yet another modified form thereof;

FIG. 5 is a perspective view of a blade detail thereof;

FIG. 6 is a side view of a modified fan blade; and

FIG. 7 is an edge elevation view of a double fan unit.

Referring now to the drawing in detail, and more particularly to FIGS. I and 2, the reference numeral 10 represents a dry grinding warp preventer according to the present invention wherein there is a fan unit 11 comprised of a plurality of radially extending blades 12, the fan having a central opening 13 to receive a shaft I4 of a surface grinder I5 which includes an electric motor I6 on a base 17, a switch l8 and a grinding wheel 19 on the motor shaft 14.

In operative use, the fan is secured by a washer 20 and nut 21 adjacent one side of a grinding wheel spacer 22 adjacent the wheel 19. The fan is slightly less in diameter than the wheel whereby rotation of the wheel and fan causes a breeze of cooling air to be directed against the surface 23 of the work 24 being ground and thus prevent the same from becoming overheated and accordingly warped during grinding operation which accordingly would result in an inaccuracy in grinding thickness.

In FIG. 3, the fan 30 is provided with blades 31 comprised of blade extensions 32 to which separate blade'elements 33 are securable by bolts 34 and nuts 35. It will be noted that engaging teeth 36 on the extensions and elements will lock the parts rigidly to prevent radial shift during rotation. Thus a means is provided wherein the blade lengths are selectively adjustable.

In FIGS. 4 and 5, a modified fan assembly 40 includes radially slidable blades 41 having central slots 42 receiving mounting pin 43. Each blade includes rotatable airfoil 44 rotatable about pin 45. The airfoil includes a weight 46 at one end whereby during rotation, the airfoil imparts a reciprocal radially inward and outward force so to cause each blade to slide on pin 43. Tension springs 47 normally return the blades radially inward.

In FIG. 6, a modified blade 60 is shown wherein rotatable propeller 61 includes a short blade 62 and longer blade 63 rotatable about pin 64 mounted on plate 65 radially slidable in guides 66 of fan blade extension 67. The plate 65 includes ears 68 against which one end of compression spring 69 bears, the other end of the spring bearing against the blade extension so to normally urge the plate radially inward.

In FIG. 7, the double fan unit 70 includes fans 71 and 72 on opposite sides of grinding wheel 73, thus increasing the air stream volume that is directed toward the work.

Blades 71 and 72 of FIG. 7 are bent to throw air not only at the giece being ground, but also into the wheel to keep the grin mg surface of the wheel clean of particles. These b ades may be bent to suit the purpose.

While various changes may be made in the detail construction it is understood that such changes will be within the spirit and scope of the present invention.

I claim:

I. In a dry grinding warp preventer, the combination of a fan unit securable adjacent a side of a grinding wheel, said fan unit including radially extending blades to direct a stream of air toward a work surface being ground wherein said blades are radially slidable each blade having a central slot receiving a mounting pin slidable in said slot, each blade having a rotatable airfoil near its outward end, said rotatable airfoil being rotatable about a pin and said airfoil having a weight and one end to cause a radial force on said blade to slide radially inward and outward during rotation. I 

1. In a dry grinding warp preventer, the combination of a fan unit securable adjacent a side of a grinding wheel, said fan unit including radially extending blades to direct a stream of air toward a work surface being ground wherein said blades are radially slidable each blade having a central slot receiving a mounting pin slidable in said slot, each blade having a rotatable airfoil near its outward end, said rotatable airfoil being rotatable about a pin and said airfoil having a weight and one end to cause a radial force on said blade to slide radially inward and outward during rotation. 